/ Dictionary / Index L lethiferous: Meaning and Definition of Find definitions for: le•thif•er•ous Pronunciation: (li-thif'ur-us), [key] — adj. Archaic. lethal. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Lethe Letitia Related Content Daily Word Quiz: arboreal Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language